Previously, in our application, we had used normal plain FTP with the UC200T and it has worked well. We used it to send data files from our embedded system to a remote FTP server.
Now, we would like to explore using FTPS. The UC200T had been configured following the instructions in the FTP & SSL AT commands manuals. We configured Filezilla Server for FTPS. In the process, we encountered some problems, and would like to ask for advice here.
The detailed test we did is listed here, including our questions:
In summary, in the two test scenarios, (i) the file transfer either did not start, and (ii) the file transfer only happened for the first 230 bytes, but the characters were unreadable (seems like some binary data). The PROC-P setting (encryption for data channel) was the only difference in the two scenarios.
We would like to seek advice in terms of any AT commands that we may have missed or set wrongly, and if there is any tips on the ciphersuite / any setting for the FTPS server side.
Thank you very much.